The present invention relates to a vehicle interior trim having a reduced glare effect at the windshield or the rear window.
Light color shades in the interior of a passenger car give an ambience that appears particularly valuable, generous, and friendly and are therefore regarded as a preferred measure of design. A light interior trim is frequently used as an option in shows cars on fairs, etc. to emphasize the valuable character of the vehicle.
However, a light interior trim is of interest not only because of design aspects, it also offers practical advantages due to the reduced sensitivity to dust and dirt as well as a considerable improvement of the climatic comfort due to the reduced heating during direct insolation.
On the other hand, light surfaces, in particular in the region of the front and rear shelves, produce disturbing reflections in the panes, thus drastically reducing the perception security in unfavorable conditions. This is one of the reasons why light vehicle interior trims have hardly played a role in series application.
It is known to solve this problem by dereflecting measures at the panes themselves. However, these techniques have not gained acceptance in practice. Antireflective coats as are used in the improvement of spectacle lenses or photographic objectives would be very expensive if they were intended to be applied to large surfaces and to be neutral in color as well. The use of xe2x80x98graded indexxe2x80x99 layers, i.e. surfaces having a smooth transition of the refractive index from glass (n=1.45) to air (n=1), would also be conceivable but virtually unusable since these surfaces have insufficient hardness and abrasion resistance and are very sensitive to dirt.
Therefore, an object of the present invention is to devise light, decoratively appealing surfaces for the vehicle interior which do not impair traffic safety due to an excessive glare effect at the panes.
The present invention provides a vehicle interior trim having a reduced glare effect at the windshield or the rear window, characterized by the following features: (a) a transparent surface layer (2) whose upper boundary surface (7) has a non-smooth structure, partial areas of boundary surface (1) being inclined toward the windshield or the rear window; (b) a mat absorber layer (5) which is arranged underneath the surface layer (2); (c) a zone which is situated between the surface layer (2) and the absorber layer (5) and which has a total reflection effect for light beams impinging into the vehicle interior at flat angles from outside; and (d) means (7,8,9) for scattering the light so that a natural lightness appearance ensues for the vehicle passenger.
Unlike the above mentioned, known measures which are directed to the pane itself, the present invention proposes to carry out the xe2x80x98dereflectionxe2x80x99 by measures at the interior, namely at the locations which are reflected in the pane and able to blind the passengers. The interior trim according to the present invention is arranged, above all, in the region of the front shelf (instrument panel) and/or of the rear shelf.
Advantageously, the angular position, the extent and/or the number of surface elements of the surface layer (2) that are inclined toward the windshield may be used for controlling the intensity of the totally reflected light and, consequently, for adjusting the lightness appearance perceived by a vehicle passenger.
The zone featuring a total reflection effect may be formed by air gaps (4) situated between the surface layer (2) and the absorber layer (5).
The zone featuring a total reflection effect also may be constituted by transparent shaped bodies situated near or at the interface between the surface layer (2) and the absorber layer (5), the shaped bodies having a refractive index which is greater than the material of the surface layer (2). The shaped bodies may be designed in a pyramid-like, cone-like, lens-like, or irregular manner and have an essentially plane base.
The upper and/or the lower boundary surface(s) of the surface layer (2) may be regularly or irregularly structured for scattering the light, and may be structured in the form of prisms, cones, knobs, grooves or waves, or is/are irregularly grained.
For scattering the light, cavities or transparent scattering bodies (8) may be included in the surface layer (2) which have a refractive index which differs from the material of the surface layer (2).
The vehicle interior trim may have an at least partially polarizing effect, the polarization plane lying in the driver""s plane of sight, and a polarization filter may be situated above or underneath the zone of the transparent scattering bodies (8) within the surface layer (2). Highly refractive fibers (9) also may produce a polarizing and at the same time scattering effect, and may be included within the surface layer (2) parallel to the driver""s plane of sight.
Scattering bodies (8) or shaped bodies may be arranged within the surface layer (2) are larger than the light wavelength, preferably in the size range from 10 micrometers to 1 millimeter. The scattering bodies (8) or shaped bodies arranged within the surface layer (2) may be dyed in neutral gray or other light color shades.